speakers, and going from 40 wpc to 50 or 60 or 75 wpc ain't gonna do it.  But getting 100+ wpc will cost you.  Consider the Emotiva separates on sale right now, a USP-1 preamp and UPA-2 (125 wpc) power amp for $759 delivered.  If you don't like them before 30 days is up you can return them for a full purchase price refund. http://www.emotiva.com/

I own a pair of 685s which I have paired with a Rotel 1062 and they have great synergy.  I tried Cambridge and NAD and neither paired well with the 685s. I would recommend picking up a used 1062 on audiogon. They come up fairly often. I think you would be qiuite happy.

Dan J